feat: loop through all validators to retrieve the public_key

[nanderstabel]

Description of change

See #67

Links to any relevant issues

#67

How the change has been tested

All test still pass.

Definition of Done checklist

Add an x to the boxes that are relevant to your changes.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes